The associations between ambient air pollution and adult respiratory mortality in 32 major Chinese cities, 2006-2010.

BACKGROUND

China has experienced increasingly severe levels of air pollution in the past decades, yet studies on the health effects of air pollution in China at a national study level, remain limited. This study assess the sub-chronic effect of ambient air pollution on respiratory mortality in the 32 largest Chinese cities.

METHODS

We employ two-way fixed effects panel data analysis and monthly air pollution and mortality panel data. We estimate associations between monthly respiratory mortality and air pollution; pollution is defined as particulate matter with aerodynamic diameter <10μm. We adjust for city characteristics, seasonality (monthly effects), and weather conditions (precipitation and temperature). We examine the associations between monthly injury mortality and air pollution to check for robustness.

RESULTS

The results show positive and statistically significant associations of air pollution with respiratory mortality. During the study period (2006-2010) a 10μg/m(3) increase in monthly PM10 concentration is associated with a 1.05% (95% CI, 0.08-2.04%) increase in adult respiratory mortality rate. The air pollution effect is the most salient in northern cities (with central heating system) during the cold season (October-April); a 10μg/m(3) increase in monthly PM10 concentrations is associated with a 1.62% (95% CI, 0.22-3.46%) increase in the elderly respiratory mortality rate. There is no statistically significant association between the young adult respiratory mortality and air pollution.

CONCLUSIONS

The elderly respiratory mortality rate in China is positively and statistically significantly associated with air pollution. The effect is largest in northern cities during cold months when coal is burned for heating.